In the field of glass bonding, there is a need for a primer that can be used under a range of conditions. One desired function of the primer is to treat the glass surface to ensure a tenacious bond between the glass and sealant (e.g., adhesive). In one application, adhesive or other sealant will be applied shortly after the primer is applied. In other applications the adhesive or other sealant is applied after a considerable period of time has elapsed. It is important in all of these applications that the primer is functional at the time when the adhesive or sealant is applied. It is common to refer to the useful functional life of the primer as its open time. This generally refers to the time between application of the primer and the time at which an adhesive or other sealant can no longer be applied to the primer and used optimally for bonding. That is, for an application involving installation of glass in an automotive vehicle, if the primer cures too rapidly and becomes intractable with which to work, then a window installer is without sufficient time to install and properly place the glass into the vehicle frame. For present glass bonding purposes (particularly for automotive applications), generally, optimum bonding use requires that the failure mode of the adhesive or other sealant to the primer be predominantly cohesive, and more specifically, substantially entirely cohesive.
Examples from the literature addressing primer materials in this field include Published U.S. Patent Application Nos. US20010041782A1, 20030100676A1; U.S. Pat. Nos. 5,010,202; 4,874,805; 4,396,681; 4,367,313; 6,875,470; EP Patent No. 1217049A1; JP Patent Application Publication Nos. JP2003-336008, JP2003-128988, JP2002-309182, and JP2002-309163, all of which are hereby expressly incorporated by reference. Two component primers may be employed and many are known to exhibit both short open time properties and long open time properties. However, two component primers generally require additional steps of labor and handling.
U.S. Pat. No. 6,133,398, incorporated by reference, describes a one-part adhesive composition including a polyurethane prepolymer, which may employ a compound containing at least one oxazolidine moiety.